This renewal application requests continued support to train Ph.D. students in the Cell and Molecular Biology (CMB) Programs within the Division of Biology and Biomedical Sciences (the "Division") at Washington University. The four CMB Programs are Molecular Cell Biology, Molecular Genetics, Developmental Biology, and Molecular Microbiology and Microbial Pathogenesis. These Programs have a history of excellence in research and education that is nationally recognized. A unique feature of these Programs is their administration by the Division, which was established more than 30 years ago with its own endowment, in recognition of the increasingly interrelated nature of all aspects of biological and biomedical research. As a result of the Divisional structure, all predoctoral programs and degree-granting units in the biological sciences at Washington University are both interdisciplinary and interdepartmental. Continued support of this training grant is proposed to be used for two main purposes: 1) to promote the professional growth of students whose research interests lie in an interdisciplinary area of crucial importance in the post-genomic era: cell and molecular biology;and 2) to foster interactions among the faculty as a means of providing new research directions and training opportunities for students.